This invention relates to an electric tooth-brush having an electric potential generating means.
A conventionally known electric tooth-brush of this type has a handle comprised of a head portion studded with bristles, and a grip portion removably coupled to the head portion. In the head portion, a head conductor member is embedded having one end exposed to the bristles and the other end exposed to one end of the head portion opposite to the bristles. The grip portion accommodates a battery and carries on its top surface a grip conductor member connected to the battery. When the grip portion is coupled to the head portion, the head conductor member is electrically connected to the battery. In use, the battery, the grip conductor member, a user body and the head conductor member constitute a closed circuit which, when a tooth paste containing fluoride is used, causes electrical permeation of fluorine ions into the teeth, thereby ensuring protection and prevention against tooth decay and pyorrhea.
Generally, after repetitions use of the tooth-brush, its bristles will be worn and torn and the tooth-brush, now being of no use, must be put in disposal. The usable term normally amounts to about one month.
When, in the conventional tooth-brush described previously, wear and tear of the bristles occurs, the head portion is put in disposal and replaced with new one but the grip portion, not subject to replacement, is put in further use. This leads to cost reduction as compared to the cost charged for disposal of the entire tooth-brush. However, the head conductor member embedded in the head portion is inseparable therefrom and therefore, upon disposal of the head portion, the head conductor member is simultaneously put in disuse even if it is still usable, resulting in a disadvantage of insufficient cost reduction. Furthermore, the head portion with the head conductor member embedded is complicated in structure.